The present invention relates generally to process control systems. More specifically, the present invention relates to a transmitter for producing a user-viewable diagnostic output representative of the operation of the transmitter.
Field transmitters are used in industrial processes to obtain information associated with the operation of the processes. Sensors located inside the field transmitters, or in communication with the field transmitters, are employed to measure process variables representative of conditions associated with the industrial processes. Examples of process variables include pressure, temperature, flow, density, viscosity, pH, conductivity, product level, turbidity, vibration, position, and any other chemical or physical property associated with the process.
Field transmitters are used, for example, to monitor process variables in chemical, gas, petroleum, and pharmaceutical plants. Typically, the transmitters are mounted on tanks, pipes, or other vessels and may communicate with industrial processes via impulse lines. The transmitters often are configured to transmit a signal representative of a process variable to a control room or other process system. The transmitters may also include a display for communicating a magnitude of the process variable or other information.
As transmitters age, or are subjected to harsh environmental conditions, operation of the transmitters can degrade and transmitter components can malfunction or fail. All electrical components, including the sensors, have the potential to malfunction or fail. In addition, impulse lines can dry out or become obstructed, affecting the accuracy of the process variable measurement.
Transmitter manufacturers have begun to incorporate diagnostic capabilities into transmitters to help assess the operation of the transmitters and facilitate preventative maintenance. Field transmitters have a limited amount of display space and power for communicating increased amounts of diagnostic information to users in a concise and easy to interpret manner. As such, there exists a need for an improved interface for communicating diagnostic information representative of the operation of a field transmitter.